CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (4,231)	$ (2,629)	$ (13,870)	$ (8,658)
Other comprehensive income (loss):
Foreign currency translation adjustment, net of taxes	197	66	323	(300)
Total comprehensive loss	$ (4,034)	$ (2,563)	$ (13,547)	$ (8,958)